| Rank | Country | broad gauge | Railways |
| Japan | | total: 23,474 km standard gauge: 3,204 km 1.435-m gauge (3,204 km electrified) narrow gauge: 77 km 1.372-m gauge (77 km electrified); 20,182 km 1.067-m gauge (13,334 km electrified); 11 km 0.762-m gauge (11 km electrified) (2006) |
| Jersey | | void |
| Jordan | | total: 505 km narrow gauge: 505 km 1.050-m gauge (2006) |
| Kenya | | total: 2,778 km narrow gauge: 2,778 km 1.000-m gauge (2006) |
| Kiribati | | void |
| Korea, North | | total: 5,235 km standard gauge: 5,235 km 1.435-m gauge (3,500 km electrified) (2006) |
| Korea, South | | total: 3,472 km standard gauge: 3,472 km 1.435-m gauge (1,342 km electrified) (2006) |
| Kosovo | | total: 430 km (2005) |
| Kuwait | | void |
| Laos | | void |
| Lebanon | | total: 401 km standard gauge: 319 km 1.435 m narrow gauge: 82 km 1.050 m note: rail system became unusable because of damage done during fighting in the 1980s and in 2006 (2006) |
| Lesotho | | void |
| Liberia | | total: 490 km standard gauge: 345 km 1.435-m gauge narrow gauge: 145 km 1.067-m gauge note: sections of railway are inoperable because of damage suffered during the civil war (2008) |
| Libya | | 0 km note: Libya has announced plans to build seven lines totaling 2,757 km of 1.435-m gauge track (2006) |
| Liechtenstein | | 9 km 1.435-m gauge (electrified) note: belongs to the Austrian Railway System connecting Austria and Switzerland (2006) |
| Luxembourg | | total: 275 km standard gauge: 275 km 1.435-m gauge (243 km electrified) (2006) |
| Macau | | void |
| Macedonia | | total: 699 km standard gauge: 699 km 1.435-m gauge (223 km electrified) (2006) |
| Madagascar | | total: 854 km narrow gauge: 854 km 1.000-m gauge (2006) |
| Malawi | | total: 797 km narrow gauge: 797 km 1.067-m gauge (2006) |